Tesla posted earnings that beat expectations on Wednesday but the electric car maker sharply lowered its fourth-quarter guidance to 30 to 35 cents a share on fewer-than-expected Model S deliveries for the year.

Analysts had expected fourth-quarter earnings guidance of about 75 cents a share.

The firm also announced plans to postpone Model X deliveries.

Shares spiked more than 8 percent on the third-quarter results in after-hours trade.

The company posted third-quarter earnings per share of 2 cents a share, compared to 12 cents per share in the year-earlier period.

Non-GAAP revenue for the quarter came in at $932 million, against the comparable year-ago figure of $603 million.

Analysts had expected Tesla to report a loss of about 1 cent per share on $889 million in revenue, according to a consensus estimate from Thomson Reuters.

The electric car maker said in its third-quarter shareholder letter that it had the highest ever quarterly deliveries at 7,785 vehicles and the highest ever peak deliveries in a single day at 907 vehicles.

However, Tesla lowered the number of expected deliveries for 2014 by 2,000 to 33,000 vehicles, citing hardware changes to the all-wheel drive Model S. The company emphasized that it is not demand constrained.

With a target price of less than $100 a share, Thompson is short the stock.

Tesla also projected production of more than 2,000 vehicles a week by the end of 2015 to meet increasing demand, while postponing deliveries of Model X from the first quarter of next year to the third quarter.

"There was an expectation that the Model X would be delayed by about a quarter," Carter Driscoll, senior analyst at MLV, told CNBC. "I think it's consistent with the company wanting to put the best product possible on the market."

Driscoll added that he is sticking to his $300 price target and buy rating.

Scott Mlyn | CNBC

Tesla shares dipped 5 percent early last week when rumors about slowing September sales made their way online. CEO Elon Musk took to Twitter to dispute the claims, saying that month set records for the electric automaker.